It's been unpleasantly warm here in the UK over the last month. I'm sure other places have it hotter, but we're not used to it and not geared up for it.
I have some old work colleagues who I set up some systems for, and I got an urgent phone call just before going on holiday: "the air conditioning failed yesterday and the power in the data centre was unceremoniously yanked - could you check the systems out?".
It turns out the servers - Sun machines - were fine. With a fine sense of self preservation they had shut themselves down gracefully due to the heat:
Jul 19 18:00:14 foobar rmclomv: [ID 690426 kern.crit]
SC initiating soft host system shutdown due to fault at MB.T_ENC.
Jul 19 18:00:15 foobar rmclomv: [ID 222544 kern.error]
SC Request to Power Off Host.
Jul 19 18:00:16 foobar rmclomv: [ID 428258 kern.crit]
TEMP_SENSOR @ MB.T_ENC has exceeded high soft shutdown threshold.
So far, all appears to be well, and I haven't seen any further errors.